The subject matter disclosed herein relates to industrial control systems, and more specifically, to droop response control industrial control systems for turbines.
Systems delivering fuel to gas turbines, that are producing power for purpose of generating electricity, often must comply with regulations that dictate specific power responses to changes in the system frequency of an electrical power grid. If frequency decreases then the governor of each gas turbine must compensate by increasing fuel flow to produce a proportional power response in order to contribute to grid frequency control. This compensation is often described as “droop” control in the electrical power producing industry.
The droop control system is called a “proportional droop governor” (or “proportional droop control system”) if a proportional controller is used rather than a proportional integral (PI) or proportional integral differential (PID) controller. The proportional droop governor is simple and robust, and has been used in power generating equipment. However, for this type of droop governor, the droop power response to a power grid frequency variation is not consistent and is dependent on ambient operating conditions, machine performance degradation and turbine initial load levels. The droop power response in some conditions could fail to meet grid authority's requirement due to this variation.
The present disclosure addresses this issue by correcting the traditional fuel flow command from the proportional droop governor, thereby making the droop power response more consistent and predictable on frequency variation.